topic Re: XP512 Striping in XP Storage

XP512 Striping

Sanjiv Sharma_1 — Wed, 16 Oct 2002 02:40:37 GMT

Hi All,

I have an XP512 serving as Datawarehouse for 1*rp8400,4*N-Class,2*L3000.

We are having 8 Array Group. Group 1-1,1-2,1-3,1-4,2-1,2-2,2-3,2-4.

LUNs are allocated to the Servers from a one or two Array Group.

I am planning to Allocate LUNs to one Server from minimum 4 Array group. Then do lvmstripe with one LUN from each Array Group.

I am having an existing volumegroup of LUNS from the same Arraygroup. I wanted to Allocate LUNs to one Server from 4 Array group. Then create a vg/lvol with Striping with one LUN from each Arraygroup.

How can I convert my existing lvol/vgs which has been stripped in the same Arraygroup to different Arraygroup online through HP-UX commands?

Thanks,
Raje.

Re: XP512 Striping

harry d brown jr — Wed, 16 Oct 2002 11:47:20 GMT

Raje,

You can't convert but you can copy your data by copy the filesystems from one lvol to another, by using cp -rp /source /target

live free or die
harry

Re: XP512 Striping

Stanislav Markovic — Wed, 16 Oct 2002 12:39:13 GMT

I don't think this can be done online, if your lvs are indeed striped (-i -I when they were created).

To create a copy of the LVs I would add new disks to the VG (or create a new one), create empty new LVs with the same sizes as the original ones, and then use dd on the raw devices.

dd if=/dev/raje-vg/rorigLV of=/dev/raje-vg/rnewLV bs=1024k

If the LVs are filesystems, you can stay online while copying, but you have to foresee an outage at the end. When you try to mount the new filesystems, they will appear "dirty", so you have to fsck them first.

If the LVs are databases, the outage will have to last for the duration of copying, or you have to use an XP-based mirroring tool like Business Copy or Raid Manager.

This is one reason for using extent-based striping (-D y -s g when creating LV), or for using VxVM instead of LVM, depending from which side you look at it.

Take care,
SM

Re: XP512 Striping

Vincent Fleming — Wed, 16 Oct 2002 13:22:59 GMT

I have 2 suggestions for you...

You could use AutoLUN on the XP, which can be used to move the LDEVs (luns) from one Array Group to another, transparently and online.

You should be able to get an evaluation copy of AUtoLUN from your hp sales rep or solutions architect.

You could also use Mirror/UX to create a mirror copy on a new set of LUNs that are spread over more Array Groups.

For the best performance, stripe accross all of your array groups.

Good luck!